2-9
Design of W-3WAY ECO-i SYSTEM Unit Specifi cations
1
2
3
4
5
6
7
8
Capacity loss caused by differences in tubing diameters
*
Capacity loss will occur if a tubing system that matches the horsepower is not selected (for example, if a tubing system was
determined and installed with no plan for extension and extension occurs later). The loss rate can be found from the graph
below.
Cooling
Heating
95
94
93
92
91
90
96
97
98
99
100
Capacity r
atio based on Gas
tube diameter (%)
Recommended Gas tubes diameter (in)
ø3/4”
ø7/8”
ø7/8”
ø1-1/8”
ø1-1/8”
ø1-3/8”
ø1-3/8”
ø1”
10
12
14
16
18
20
26
30
35
40
45
46
47
48
(Reading the graph)
<Example 1>
Currently a 16 HP system and ø1-1/8" Gas tubings are used. Subsequently the system is expanded, with 16 HP added to the
same tubing system.
Horsepower after extension: 16 + 16 = 32 HP
From the graph above: Cooling: Capacity ratio is 90.8%. Actual capacity = 32 × 0.908 = 29.1 HP
Heating: Capacity ratio is 96.0%. Actual capacity = 32 × 0.960 = 30.7 HP
1. Model Selecting and Capacity Calculator
Gas tubing size (in.(mm))
1/2"
(12.7)
5/8"
(15.88)
3/4"
(19.05)
7/8"
(22.22)
1"
(25.4)
1-1/8"
(28.58)
1-3/8"
(38.1)
90
°
elbow
1
1.1
1.4
1.6
1.7
1.9
2.5
45
°
elbow
0.8
0.9
1
1.2
1.3
1.4
1.8
U-shape tube bent
(R2–23/64–3–15/16 in.)
3
3.4
4.1
4.7
5.1
5.6
7.4
T r ap bend
7.5
9.2
10.5
12.5
14.1
15.4
19.2
Y-branch distr ibution joint
Equivalent length conversion not needed.
Ball v alve f or ser vice
Equivalent length conversion not needed.
1-6. Straight Equivalent Length of Joints
Design the tubing system by referring to the following table for the straight equivalent length of joints.
Table 2-8 Straight Equivalent Length of Joints
Unit: ft.
TD831139̲Sec2̲p01-17.indd 9
TD831139̲Sec2̲p01-17.indd 9
2008/04/17 15:31:33
2008/04/17 15:31:33